Path Computation Policy Information Model (PCPIM) draft-bryskin-pce-pcpim-00.txt
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Transcript of Path Computation Policy Information Model (PCPIM) draft-bryskin-pce-pcpim-00.txt
Path Computation Policy Path Computation Policy Information ModelInformation Model
(PCPIM)(PCPIM)
draft-bryskin-pce-pcpim-00.txtdraft-bryskin-pce-pcpim-00.txt
Igor BryskinIgor Bryskin Lou Berger Lou Berger
IETF-67
Draft Background
• The PCE architecture introduced the concept of PCE policy
• Policy-Enabled Path Computation Framework defined use of PCIM– In draft-ietf-pce-policy-enabled-path-comp– PCIM = Policy Core Information Model (PCIM)
• This draft defines specifics on PCIM use– Defines the Path Computation Policy Information
Model (PCPIM) as sub-class of PCIM
IETF-67
Draft Objectives
• PC Policy semantics:– PC Policy class definition for
• PC constraints• PC capabilities• PC variables and values• PC actions
• Allow for future extendibility• Work within PCE Policy Framework
– Leverage existing policy modeling tools • PCIM/PCIMe
IETF-67
Requirements for PC Policy Information Model
• Reuse of existing policy infrastructures (e.g. PCIM) management tools, access and communication protocols
• Support for various policies and policy configurations
• Support for policy-ignorant nodes • Fault tolerance and recovery • Scalability• Security and denial of service
considerations
IETF-67
PCPIM Design Goals
• Model policies in a way close to how humans tend to think about policy
• Rule-based modeling• Hierarchical organization of information• Goal-oriented policy definition• Policy domain scope rather than device scope• Device-, vendor-independent modeling (using roles)• Reusability of policy constructs• Policies must enforceable• Independency of PC methodology• Easy extensibility
IETF-67
Framework Example Configuration:Single PC Policy Repository
PC Policy Management
PC Policy Repository(based on PCPIM)PCC-PDP PCE-PDP
PCC-PEP PCE-PEP
Policy A Policy B
e.g. COPS, COPS-PR e.g. COPS, COPS-PR
PCC-PCE communication protocol
IETF-67
PCIM Background: Policy Rule Basics
PolicyRule
PolicyCondition (s) PolicyAction (s)
PolicyConditionInPolicyRule association (s)
PolicyActionInPolicyRule association (s)
IETF-67
“Simple” PCIM Policy Rule
PolicyRule
SimplePolicyCondition(s) SimplePolicyAction(s)
SimplePolicyConditionInPolicyRule CompoundPolicyConditionInPolicyRuleSimplePolicyActionInPolicyRuleCompoundPolicyActionInPolicyRule
CompoundPolicyCondition(s) CompoundPolicyAction(s)
IETF-67
Modeling of PC Constraints
PolicyRule=>PcPolicyPcReqRspComponent (mandatory, relaxation priority)=> PcPolicyPcReqRspComponent sub-class
SimplePolicyCondition(s) SimplePolicyAction(s)
CompoundPolicyCondition(s) CompoundPolicyAction(s)
SimplePolicyConditionInPolicyRule CompoundPolicyConditionInPolicyRuleSimplePolicyActionInPolicyRuleCompoundPolicyActionInPolicyRule
IETF-67
An Example of a PC Constraint
• PcPolicyBandwidthConstraint class models TE link bandwidth availability constraint– Derived from the PcPolicyPcReqRspComponent class– Properties:
• Bandwidth• Priority• Directionality
– Can model the following logic:if(PcPolicyServiceBandwidthVariable !=0) then banwidthConstraint.
bandwidth = PcPolicyServiceBandwidthVariable;
bandwidthConstraint.directionality = PcPolicyServiceBandwidthDirectionalityVariable;
bandwidthConstraint.priority = PcPolicyServiceBandwidthPriorityVariable; bandwidthConstraint.mandatory = TRUE’
IETF-67
Details
• There’s a lot and we’re out of time…
• A detailed version of this presentation is available
IETF-67
Modeling “Request Path Computation” PC Action
PolicyAction=>PcPolicyAction(PCCID, PCEID)=>PcPolicyActionRequestPathComputation
PcPolicyReqRspSet(s)
PcPolicyReqRspComponent1
PcPolicyReqRspComponent2
PcPolicyVariable1
PcPolicyVariable2
PcPolicyVariable3
IETF-67
Modeling “Send Path Computation Response” PC Action
PcPolicyReqRspSet(s)
PcPolicyReqRspComponent1
PcPolicyReqRspComponent2
PcPolicyVariable1
PcPolicyVariable2
PcPolicyVariable3
PolicyAction=>PcPolicyAction(PCCID, PCEID)=>PcPolicyActionSendPathComputationResponse
IETF-67
Next Steps
• Add formal class definitions
• Integrate comments
• Formalize contribution from others
• We welcome input and discussion on this draft -- in private or on list!
Thank YouThank You